\begin{Schunk}
\begin{Sinput}
 xvals <- seq(0,10,length.out=1000)
 chisquare1 <- dchisq(xvals, df=1)
 chisquare2 <- dchisq(xvals, df=6)
 matplot(xvals, cbind(chisquare1, chisquare2), type="l", xlab="possible values of x", ylab="probability of x",  ylim=c(0,1), main="Chi-Square Probability Densities")
 text(.4, .9, "df=1", pos=4, col=1)
 text(4, .2, "df=6", pos=4, col=2)
\end{Sinput}
\end{Schunk}
